John McGreal's first goal of the season rescued Joe Royle's side 18 minutes from time after Lloyd Owusu's first for Reading had put the home side in front.
Owusu, making his first start at home in a loan spell from Sheffield Wednesday, headed home on 62 minutes to complete a superb sweeping move from the home side.
Reading keeper Marcus Hahnemann was allowed to play on after an offside flag against Ipswich and quickly swept a kick to Scott Murray on the right wing.
The lively Murray ran into space and lobbed in inch-perfect cross for the onrushing Owusu to head expertly into the far corner and beyond the reach of goalkeeper Kelvin Davis.
But Ipswich hit back ten minutes later with a deserved equaliser created for McGreal by substitutes Martijn Reuser and Dean Bowditch.
Reuser's corner was helped on by Bowditch and landed at the feet of McGreal, who turned and poked home in acres of space.
That was a relief for Ipswich, who dominated for long periods but failed to create enough cutting-edge chances to underline their superiority.
Reading missed England Under-21 midfielder Steve Sidwell and top scorer Nicky Forster, described by Ipswich boss Joe Royle as "their best two players".
But Owusu was an able deputy, threatening with a couple of first-half headers before making the breakthrough on 62 minutes.
And when Owusu and Royle's former Manchester City striker Shaun Goater made way for young substitutes, Dave Kitson and Dean Morgan late on, Reading nearly snatched back victory.
Morgan set up impressive full-back Graeme Murty for a stinging shot that was beaten away by Ipswich keeper Kelvin Davis.
And when some neat Morgan footwork undid McGreal and his defence late on, the build-up deserved a better finish than his wild lash into the stands.